Hydraulic medium



June 13, 1944. B. J. CRAIG 2,350,990

HYDRAULIC MEDIUM I Filed Oct. 12; 19427 Patented June 13, 1944 UNITED STATE SPATENT GFFECE 16 Claims.

This invention relates particularly to a novel hydraulic medium.

The general object of the invention is to provide a novel hydraulic medium which has energy storing and releasing properties.

A more specific object of the invention is to provide a novel mobile mass wherein the mass has such properties that it provides a smooth normal action tending to cushion impulses and which tends to cushion variations in pressure and/or to restore the smooth flow and/or to avoid surges.

A further obyect of the invention is to provide a novel mobile medium which is elastic and/or resilient and/or compressible and/or has ene y storing and releasing properties so that it may act and react, and be acted upon while performing its function.

Another object of the invention is to provide a novel fluid-like mass suitable for use in fluid transmissions, shock absorbers, clutches, or other energy-absorbing and/ or transmitting devices.

Another object of theinvention is to provide a novel mobile mass composed of discrete particles which may be distributed throughout a fluid matrix.

Other objects and the advantages of this invention will be apparent from the following de scription taken in connection with the accom panying drawing wherein:

a fluid turbo device in which the hydraulic medium may be employed;

Fig. 2 is a central sectional view showing one of the members employed in the medium;

Fig. 3 is a central sectional view showing a modified member before vulcanization;

Fig. 4 is a view similar to Fig. 3 showing the modified member after vulcanization;

Fig. 5 is a central sectional. view showing a further modified member;

Fig. 6 is a fragmentary enlarged sectional view similar to Fi 1 showing the fluid mass in the turbo device;

Fig. 7 is a sectional view, partly in elevation and partly diagrammatic, showing an apparatus for making the members;

Fig. 8 isan enlarged fragmentary sectional view showing a mold member;

Fig. 9 is an enlarged plan development of one of the mold members;

Fig. 1" is a sectional view-showing an apparatus for making a modified member; and

Fig. 11 is a sectional view showing a further modified member.

ters the invention is disclosed as employed in a hydro-dynamic device II] which is shown as a coupling but it will be understood that is by way of illustration only and that the invention may be employed for many other purposes.

The device In is shown as used with a flanged member l3 which may be suitably driven. A housing i4 is connected to the member l3 by bolts IE. The housing 14 includes a primary or turbo vane wheel member 16 and. the housing is disposed about a secondary turbo vane wheel member llwhich mates with the turbo vane wheel member It. The turbo vane wheel I? is secured to a shaft l8 supported on a bearing is disposed in the housing it. A suitable seal is maintained at 20.

The fluid turbo elements 16 and I1 include vanes 23 and 26, respectively, and their walls are contoured to form fiuid receiving pockets 25 which are suitably spaced. The vanes 23 and 24 are notched as at 25 to receive semi-circular guide rings 21 which are suitably welded or otherwise secured in place.

According to the present invention, the hydraulic medium comprises a mass which in one disclosed form consists of a plurality of small members or particles indicated at 2B and shown as spherical and having a cavity 29 filled with compressed gas. The members 28 may be made of rubber, artificial rubber or other material having the requisite properties, and if desired the members may have particles 30 (Fig. 2) oi? metal or other material embedded therein to vary their specific gravity. The particles 30 may be inserted in the material from which the members 28 are made and they are preferably removed somewhat from the surface 3| of the members 30.

The members 28 may be employed alone as a driving medium or they may be employed with a suitable liquid such as oil or other material which does not seriously aiiect the material of which the members are made. The liquid employed is preferably in sufilcient quantity to at least fill the voids between the members 28 as shown at 32 in Fig. 6.

The amount of liquid and the size and weight of the members 28 may be varied to suit the particular requirements of the structure with which they are employed by controlling the size of the cavity 29, the wall thickness, and the presence or absence of particles 30. The specific gravity a multi-cylinder gasoline engine.

- immediately store added energy so that less circulation disturbance will result. The stored energy will be later released in accordance with the driving conditions.

This result is true, to a degree, regardless of whether the changes mentioned are large as duringrapid acceleration with high slip or whether they are small as in normal periodically variable torque produced by In each condition of driving the medium automatically assumes a definite energy content from the imposed conditions and this energy content remains normal until the conditions which produce it change. This energy content may be considered as composed of the kinetic energy of the flowing material and the potential energy of compression of the particles.

On a departure from normal the mobile mass at once becomes an energy storing and releasing means which at once stores the energy above a normal and releases this stored energy under conditions below a normal. The storing and re- -leasing of energy quickly balances whereupon the mobile mass operates under a new normal 01' contained energy content.

Regardless of the time required to store or .release energy the tendency is to prevent or lessen the efiect of abrupt torque increase or load input etc. and the medium is constantly taking the extremes of torque increase or load input and is reducing the eflfect of these extremes without loss of operating-efficiency and while maintaining a normal balanced state between energy storing conditions and energy releasing conditions. Thus by virtue of the properties of the mobile J massthe periodic torque variations delivered by .an internal combustion engine are largely damped out so that a smoother drive results. Further, the turbulence and surging occurring the pre under certain driving conditions with vious fluid are largely eliminated.

The members 28 may bemade in several ways for example, by means of the apparatus indicated at 35 in Fig. 7. As shown, the apparatus includes upper and lower drums 36 and 31 which are suitably supported for rotation. Each drum is hollow and mounted on a hollow shaft 38 which communicates-with the interior of the drum and with the atmosphere.

As shown in Figs. 8 and 9 each of the drums 1 is provided on its exposed surfacewith a plurality of substantially hemispherical mold cavities 39 which communicate through holes 40 with the interior of the drum. Each mold cavity 33 is surrounded by a more or, less sharpened peripheral edge. portion 4|. The portions 4| on the two drums are in substantial engagement where the drums are tangent. a

The apparatus 35 is preferably'arranged in.a

room 42 where air under pressure is maintained.

7 Access to the room 42 may be through a-suitable airlock 4 The apparatus 35 includes supports 44 for rolls-of rubber, plastic material, or other the drums 38 and 37 are rotated the stock 45 is carried about the drums.

The drums being hollow and being bled to the atmosphere through the hollow shafts, there is a constant flow of air from the room 42 into the drums through the holes ,40 and from the drums through the hollow shaft 38 to the atmos phere so that the interior of the drums is under less pressure than .the exterior thereof. The

stock 45 being more or less plastic is forced by the greater air pressure in the room 42 into the mold cavities 39 and r'otates'with the drums until the edge portions 4| contact. The layer in .each mold cavity forms one-half of a ball and when the two halves are brought together a complete ball is formed as shown in Fig. 8. The drums may be heated so that a slight cure results as the drums rotate. The two united layers of stock with the minute hollow, rubber balls formed therein and with the balls still united by fins pass from the drums and is carried on sup porting devices 45 through a vulcanizer 41. The

stock 45 and the construction is that when 5 cover 54.

minute balls are preferably held in sheet form until vulcanization is complete, whereupon they are separated in any desired manner as by multiple punches, for instance.

In order to prevent excess leakage through the holes 40 which are not sealed'by the sheet stock,

endless elastic belt members 48 (see Fig.1) may be employed. These members pass over rollers 49 and are dragged along by the adjacent drums -so that the holes 40 beneath the belts 48 are closed, thus reducing leakage.

The two halves of the balls having been united in a room filled'with compressed air, the balls when finished are inflated by the air which they entrapped, the pressure of this air having been predetermined.

In Figs. 3 and 4 another type of member is in.- dicated at 50. This member may be made by taking a core 5| which'may consist of some -suitable material, such as amorphous graphite combined with a gas releasing material, such as ammonia powder and a binder such as clay to form .a pellet. The core 5| isthen covered with latex or similar material and vulcanized with the gas liberated from the ammonia powder serving to provide pressure for.vulcanization and for in- Lilation after the member is vulcanized. The

member maybe vulcanized in a chamber filled with compressed air which will prevent the gas I liberated by the ammonia powder from expand"- ing the latex cover unduly. The graphite and clay 5| in the member 50 serve to add weight to the finished product.

In Fig. 5 the member 52 includes a ball 53 made of metal or other suitable material with a resilient and elastic covering 54 as of sponge rubber arranged thereon. An outer'covering or skin 55 of resilient rubber may be applied-to the In Fig. 1 the member 51 includes a. porous core member 53 which may be made of cork and which has a cover 59 of resilient material such as rubber.

To make the members 51 I may employ an apparatus which includes a housing 30 having a funnel shaped container 6| in the top thereof.

The container has. a cylindrical hopper portion 62' at the bottom thereof in. which a rotatinghopper gate 63 is-mounted. Communicating with the interior of the housing I show an air pressureconduit 64 with a constant pressure 0' "let valve 65 therein which determines the minimum air pressure within the housing 60.

the container 6!.

it remains substantially uniform and stable under Also communicating with the interior of the housing 60 I show an air outlet 68 with a constant pressure inlet valve 61 therein which determines the maximum air pressure within the housing. I

Extending into the housing I show a plurality of latex jets 58. The bottom of the housing is tapered inwardly as at 69 and has a cylindrical hopper portion 10 at the bottom thereof in which a rotating hopper gate H is mounted.

In operation, porous particles 58 are placed in Air pressure is maintained within the housing 60 by means of the air pressure conduit 64 and is maintained above a desired minimum pressure by means of the constant pressure outlet'valve 65. The air pressure is kept below a desired maximum by means of the constant pressure inlet valve 61. As the rotating hopper gate 63 is rotated, the small particles of porous material are allowed to fall into the housing and through the paths of the latex sprays where they become coated with latex which is air vulcanized when the particles reach the bottom portion of the housing where they may be removed by means of the rotating hopper gate H. Thus it may be seen that compressed air is entrapped in the pores of the porous particles and sealed therein by the coating of resilient rubber 59 about each particle as shown in Fig. 11.

The members 28 and 50, 52 and 51, are compressible as well as resilient and elastic due to the contained gas, so that when these members are employed with a liquid or alone they form a liquid-like mass which is compressible, elastic and resilient.

.The size of the members used may be suitably varied to suit the conditions in each installation; also the pressure within the contained members. their wall thickness, resiliency, elastlcity, etc., will be suitably determined by the requirements.

The specific, gravity of the members may be varied as required. For instance, the members 28 when used with a liquid may have substantially the same specific gravity as that of the liquid, The members 50 preferably have a specific gravity less than that of the liquid while the members 52 preferably have a greater specific gravity than that of the liquid.

The compressible members or particles may be made of. such material as will permit them to perform their function and remain stable and substantially unaltered by the fluid in which they are placed. The material, for example, may be natural rubber; vulcanized synthetic rubbers such as Buna-S rubber, a synthetic of the butadiene co-polymer type, neoprene, a synthetic of the chloroprene polymer type, butyl rubber. a synthetic'of the isobutylene polymer type having small quantities of other dioliflnes such as isoprene or butadlene; non-vulcanizable elastic synthetics such as koroseal, a plasticized vinyl chloride polymer; and where porous members such as cork particles or particles of porous rubber-like material are used as cores, they may, for example, be covered with the materials just mentioned.

The liquid employed may be any liquid which has suitable viscosity at the temperature employed and which does not seriously impair the members or particles in the liquid. For example, the liquid may be a mineral oil; for example, S. A. E. 30 lubricating oil; vegetable oils such as linseed oil, soya bean oil, castor oil; alcohols as grain alcohol, glycerine, ethylene chloride, etc.

extremes of working conditions, and the members are such that they will not coalesce or compact together and they are of such character that they will not be unduly tensed under their normal working conditions.

The fluid mass instead of including individual members, may include a mass of latex or similar material cured so that it maintains its mobility and flow characteristics and which has the compressible and/or other properties required.

Having thus described my invention, I claim:

1. A hydraulic medium comprising a liquid, and discrete, resilient, hollow, independently walled, inflated members distributed throughout the liquid, the liquid being of suitable viscosity at the temperature employed and being of such character that it does not impair the members suspended therein.

2. A hydraulic medium comprising a stable mobile mass including a fluid and hollow elastic walled, inflated, members which are movable in and with the mass, the fluid being of suitable viscosity at the temperature employed and being of such a character that it does not impair the members suspended therein.

3. A hydraulic medium comprising a stable mobile mass including a fluid and hollow res lient walled,.inflated, members which are mov able in and with the mass, the fluid being of suitable viscosity at the temperature employed and being of such a character that it does not impair the members suspended therein.

4. LA hydraulic medium comprising a stable mobile mass including a fluid and hollow elastic walled, inflated, compressible particles which are movable in and with the mass, the fluid being of suitable viscosity at the temperature employed and being of such character that it does not impair the particles suspended therein.

5. A hydraulic medium comprising a stable mobile mass including a fluid and hollow elastic .walled, inflated, compressible, porous particles which are movable in and with the mass, the fluid being of suitable viscosity at the temperature employed and being of such character that it does not impair the particles suspended therein.

6. A hydraulic medium comprising a stable mobile mass including a fluid and hollow, compressible members which are movable in and with the mass, the fluid being of suitable viscosity at the temperature employed and being of such character that it does not impair the members suspended therein.

7. A hydraulic medium comprising a stable mobile liquid-like mass including a fluid and nonsuitable viscosity at the temperature employed The medium is preferably of such a nature that and being of such character that it does not impair the members suspended therein,

9. A hydraulic medium comprising a stable, mobile mass including a fluid and discrete, noncoalescing, hollow members which are movable in and with the mass, the fluid being of suitable viscosity at the temperature employed and being of such character that it does not impair the members suspended therein.

mass comprising a continuous fluid phase and a discontinuous phase of discrete, hollow, flexible walled, compressible, resilient particles the fluid phase being of suitable viscosity at the temperature employed and being of such character that itdoes not impair the particles suspended therein;

11. A hydraulic medium comprising a liquid phase, and non-gaseous, non-coalescing, potential energy storing and releasing compressible hollow particles distributed throughout the 1iquid phase, the liquid phase being of suitable Viscosity at the temperature employ'd and being of such A character that it does not impair the particles suspended therein.

12., A hydraulic medium comprising a liquid phase, and a plurality of discrete particles distributed throughout the liquid phase, the particles being hollow and independently walled, at least a portion of the particles being inflated, the liquid phase being of suitable viscosity at the temperature employed and being of such character that it does not impair the particles suspended therein. i

13. A hydraulic medium, comprising a continuous liquid-like phase, and a discontinuous phase, the discontinuous phase including non-coalescing, potential energy storing'and releasing, inflated, particles which are adapted to store and release energy which has been applied to the continuous phase, the particles being hollow and independently walled, the liquid-like phase being of suitable viscosity at the temperature employed and being of such character that it does not impair the particles suspended therein.

'14. A hydraulic medium comprising a low viscosity liquid having potential energy storing and releasing hollow, flexible walled, compressible members therein which are of a specific gravity differing from that of the liquid and movabl in and with the liquid, the liquid being of suitable viscosity at the temperature employed and being of such character that it doesnot, impair the members suspended therein.

15. A, hydraulic medium comprising a mobile fluid having energy storing and releasing hollow, flexible walled, compressible members therein which have substantially the same specific gravity as that of the fluid and which are movable in and with the fluid,.the fluid being of suitable viscosity at the temperature employed and being of such character that it does not impair-the members suspended therein.

16. 'A hydraulic medium comprising a potential energy storing andreleasing mobile mass including discrete, hollow members, each member having a thin flexible wall, the walls being independent 01 each other and of such a character that the members do not coalesce, the members being freely movable throughoutthe mass and being movable with the mass, the mass bein stable at the temperature employed.

BURNIE J. CRAIG. 

